Cam actuated tongs having magnetic drag means



Sept. 8, 1964 A. L. GEORGE 3,147,652

CAM ACTUATED TONGS HAVING MAGNETIC DRAG MEANS Filed March 5, 1962 4 Sheets-Sheet 1 A/berz L. Geo/ye /Z7 INVENTOR.

BY a M ATTO/P/VE w CAM ACTUATED TONGS HAVING MAGNETIC DRAG MEANS Filed March 5, 1962 A. L. GEORGE Sept. 8, 1964 4 Sheets-Sheet 2 ii I A/berf Z. 680/96 INVENTOR.

CAM ACTUATED TONGS HAVING MAGNETIC DRAG MEANS Filed March 5, 1962 A A. L. GEORGE Sept. 8, 1964 4 Sheets-Sheet 3 A/ber 1. George INVENTOR.

Sept. 8, 1964 A. GEORGE 3,147,652

CAM ACTUATED TONGS HAVING MAGNETIC DRAG MEANS Filed March 5, 1962 4 Sheets-Sheet 4 A/berz A. George INVENTOR.

United States Patent 3,147,652 CAM ACTUATED 'IQNGS HAVING MAGNETIC DRAG MEANS Albert L. George, Lafayette, La., assignor to Lamb Rental Tools, Inc a corporation of Louisiana Filed Mar. 5, 1962, Ser. No. 177,357 Claims. (Cl. 81-57) The present invention relates to a tong for gripping tubular members and imparting rotary motion thereto, and more particularly, to an improvement which positively urges the jaw segments of a power operated tong to engagement with a tubular member and which also aids in releasing the jaw segments from engagement with a tubular member.

At the present time, various types of power operated tongs are provided whereby a rotary motion or torque may be imparted to a tubular member so as to threadedly connect the tubular member to another member or to disconnect tubular members. More particularly, in the drilling and completion of well bores, it is necessary to lower a long strong of pipe into a well bore in the earths surface or to remove the pipe string from the well bore. This string of pipe is composed of a plurality of joints or sections of pipe of predetermined length, such as 20, 30, or 40 feet, and threads are provided on each of the joints of pipe whereby they may be threadedly connected together as the pipe is lowered into the well bore and thereafter disconnected as they are removed from the well bore.

Various types of mechanical means have been proposed for providing a frictional means in a tong for engaging tubular members or pipes which frictional means creates a drag means or effect so that jaws in the tong move radially to engage and grip a pipe. The construction and arrangement of the mechanical drag means heretofore used in tongs has been undesirable in that it does not function properly and causes undue wear on other components of the tong. Also, the mechanical drag means creates a friction on some parts of the tong which tends to nullify the desired result of the drag means.

The present invention provides a drag means in a tong for overcoming the above and other objections in a drag means for a tong.

Still another object of the present invention is to provide a magnetic drag means in a tong.

A further object of the present invention is to provide a magnetic drag means in a tong which may function at any desired point circumferentially of the pipe to move the tong into gripping engagement with the pipe.

The advantages and construction of the invention will become more apparent from a consideration of the following description and drawings wherein:

FIG. 1 illustrates the rotary ring of the present invention with the jaw segments thereon positioned about a tubular member to be engaged;

FIG. 2 is a sectional view on the line 22 of FIG. 1 and shows one form of the drag means to be used in the present invention;

FIG. 3 is a partial view somewhat similar to FIG. 1 and illustrating in dotted line another form of drag means;

FIG. 4 is a sectional view on the line 44 of FIG. 3 and illustrates another form of drag means which may be used in the present invention;

FIG. 5 is a perspective view showing the complete tong of the present invention opened and ready to be positioned about a tubular member;

FIG. 6 is a sectional view on the line 6-6 of FIG. 5 to illustrate additional structural details of the segmented rotary ring as well as illustrating the roller means for supporting the rotary ring in the housing and the manner 3,147,652 Patented Sept. 8, 1964 of supporting certain of the jaw segments on the segmented ring;

FIG. 7 is a perspective view on the tong of the present invention showing it in position on a pipe;

FIG. 8 is a sectional view on the line 8-8 of FIG. 7 and illustrates the locking means for holding the segments of the rotary ring in rigid relationship when the tong is actuated;

FIG. 9 is a sectional view on the line 9-9 of FIG. 8 showing further structural details of the segmented ring locking means; and

FIG. 10 is a view similar to FIG. 1 but shows the position of the main jaw segment relative to the rotary ring when engaged with a pipe or tubular member.

Attention is first directed to FIG. 5 of the drawings wherein a tong is illustrated generally by the numeral 10 on which tong the present invention may be employed. The tong 10 as shown and described is segmented so that it may be opened and positioned about a tubular member. In FIG. 5, the tong 10 is shown as being opened for receiving a tubular member therein whereby the segmented tong may thereafter be closed about the tubular member and rotation imparted to the rotary ring and jaw segments carried by the rotary ring whereby the tubular member may be rotated. The tong 10 includes the housing designated generally at 11, which housing is shown as being hollow and including the bottom wall 12, sidewall or peripheral end wall 13, and top wall 14. The housing 11 provides a support for a rotary ring and jaw segments carried on the rotary ring and rotation is imparted to the rotary ring when the tong is engaged about a pipe, and the jaw segments are adapted to move radially and grip the pipe to rotate it.

The present invention is described in great detail in connection with its use and application on the particular type of tong 10; however, it can be appreciated that the invention may be applied and used on any tong which has a rotary ring and means thereton to engage and grip a pipe. The description of the invention in connection with the particular tong 10 described herein is for purposes of illustration only.

The housing 11 formed by the walls 12, 13, and 14 is cut as illustrated in FIG. 5 of the drawings to form the housing into the three portions or segments 15, 16, and 17. The segment 15 may be designated the main housing and the segments 16 and 17 are connected to the main segment portion 15 at the pivot points 16 and 17', respectively.

The main segment portion 15 of the housing 11 is in a general Y configuration as shown in FIG. 5 and in FIG. 7 with the segments 16 and 17 mounted on the legs 15' and 15", respectively, of the housing segment 15 as illustrated in FIG. 5 of the drawings. The lower wall 12 and top wall 14 extend laterally from the end wall 13 a suitable distance so that the segments 15, 16, and 17 when closed as illustrated in FIG. 7 define a substantially circular opening 18 in which the tubular member 19 is received. Each segment 15, 16, and 17 of the housing 11 is arcuate and defines a housing portion for receiving the segmented rotary ring designated generally at 32 and jaw segments 37, 38, and 39.

The pivot points 16 and 17' for the segments 16 and 17, respectively, may assume any suitable construction, and as illustrated in the drawings, pivot pins 16a and 17a of suitable size are provided which are connected into the top wall 14 and the bottom 12 of the main segment 15 and also extend through reinforcing brackets 20. There are four reinforcing brackets which are secured on the top and bottom of legs 15' and 15" by any suitable means such as support blocks 21 which are welded to the top 14 and bottom 12 and to the reinforcing brackets 20.

Brackets 22 and 22' secured to the top and bottom of each of the segments 16 and 17, respectively, extend from each of the segments to overlap the legs 15' and 15", respectively, and fit beneath the reinforcing bracket 21} on each of the legs 15 and 15" as illustrated in FIG. of the drawings. The pivot pins 16a and 17a shown in FIG. 5 extend through the reinforcing brackets 20 and the rearwardly extending brackets 22, 22 mounted on the top of each of the segments 16 and 17, respectively, and are threadedly secured in the upper wall 14 of the main segment 15. A similar pivot pin 16a and 17a extends through the reinforcing brackets 21), and the rearwardly extending brackets 22, 22 on the bottom of each of the segments 16 and 17 and are threadedly secured in the bottom wall 12 of the main segment 15.

This permits the housing 11 to be opened up easily and quickly as shown in FIG. 5 of the drawings for receiving the tubular member 19 as shown in FIG. 7 therein. When the housing 11 is closed about the tubular member 19, the latch designated generally by the numeral 25 functions to lock the segments 16 and 17 relative to the main segment 15 to prevent relative movement of the segments or opening of the segments as the tong is in operation. The latch or lock means 25 includes the projection or lug 26 mounted on one of the segments such as the segment 17 illustrated in FIG. 5 of the drawings and the latch means 27 which is mounted on the bracket 28 formed on the other segment 16 as illustrated in FIG. 5 of the drawings. A pivot pin 29 is adapted to extend through each of the brackets 28 and the latch member 27 to hold the latch member in position. If desired, a spring (not shown) may be provided beneath member 27 so as to urge the latch member 27 into engagement with the lug 26 when the segmented housing is closed about tubular member 19. In order to open the housing, the latch member 27 is depressed towards the tong and against the action of the spring so that the member 27 may move out and away from the lug 26 whereupon the housing may be opened.

A plurality of roller means is illustrated generally at 31 in FIGS. 5 and 6, which roller means are mounted at spaced intervals in each of the housing segments 15, 16, and 17 and provide a means for supporting the rotary ring 32. The outer periphery 33 of the rotary ring 32 is provided with gear teeth 34 so that rotary ring 32 may be rotated thorugh a gear train (not shown) which is mounted in the housing 11 and connected by any suitable means to the power source illustrated in dotted line at 36 in FIG. 5. The rotary ring 32 in turn supports the jaw segments 37, 38, and 39 thereon whereby the segments may engage the tubular member 19 and impart rotation thereto.

A cam surface arrangement illustrated generally by the numeral 40 is provided on the ring 32 and at least one of the jaw segments whereby all of the jaw segments may be moved into operative engagement with the tu bular member 19 when rotation is imparted to the rotary ring 32, as will be described in greater detail hereinafter.

As more clearly seen in FIG. 1 of the drawings, the rotary ring 32 is also segmented so that it can be opened or spread apart simultaneously when the housing 11 is spread apart and thereafter closed about the tubular member 19 as the housing 11 is closed about the tubular member.

The rotary ring 32 includes the main segment 41 with the segments 43 and 42 being pivotally connected to the main segment 41 by any suitable means such as the pivot pins 44 and 45'. Each of the rotary ring segments 41, 42, and 43 includes a central plate 45 with an upper plate 46 and a lower plate 47 secured thereto by any suitable means such as bolts or the like as illustrated at 48 and as best seen in FIG. 1 and FIG. 6 of the drawings. It will be noted that the central plate 45 is substantially wider than the upper and lower plates 46 and 47 and that the upper and lower plates 46 and 47 are positioned adjacent but spaced from the outer periphery or edge 33 of the central plate 45.

The upper plate 46 on the main segment 41 and the lower plate 47 on the main segment 41 extend beyond the ends of the central plate 45 so as to overlap the central plate 45 of each of the segments 42 and 43, as can be seen in FIG. 1 of the drawings. Also, the central plate 45 of the segment 41 is illustrated as terminating at 51) in the arcuate recess, and the central plate 45 of each of the segments 42 and 43 terminates in the arcuate projections 511a which interfit the recess 56. It will be noted that the central plate 45 of each of the segments 42 and 43 fits between the extended upper and lower portions 46 and 4'7 of the main segment 41 shown in FIG. 1 of the drawings. The pivot pins 44 and 45' extend through the upper and lower plates 46 and 47 which are mounted on the main segment 41 of the rotary ring 32 and extend through the central plate 45 of each of the segments 42 and 43 whereby the segments 42 and 43 are pivotally mounted on the main rotary ring segment 41.

The foregoing structural arrangement enables the rotary ring 32 to be quickly and easily opened when the housing 11 is opened and thereafter closed about a tubular member as the housing 11 is closed about the tubular member. Of course, the ring segment 41 as well as the segments 42 and 43 must be in a predetermined position in the housing 11 to enable the tong 11 to be opened, and if desired, a suitable marking 1611 on the housing 11 and 161 on ring 32 may be utilized to visually indicate when the ring 32 is aligned in the housing 11 so that the tong 11) can be opened. However, when the rotary ring 32 is closed about the tubular member 19 as shown in FIG. 1 of the drawings, the segments of the rotary ring and the segments of the housing 11 are locked against relative movement. Thereafter, when power is supplied through 36 and the gear train to the rotary ring 32, rotation is imparted to the rotary ring 32 comprising the segments 41, 42, and 43 so as to in turn engage the jaw segments 37, 38, and 39 with the tubular member 19 and disengage the jaw segments 37, 38, and 39 from the tubular member 19 when desired.

The roller means 31 for supporting a rotary ring 32 is best illustrated in FIG. 6 of the drawings, and it is to be noted from FIG. 5 of the drawings that a plurality of roller means 31 is provided in each of the housing segments 15, 16, and 17 for supporting the roller ring 32 and the jaw segments 37, 38, and 39 properly in the housing.

As shown in FIG. 6 of the drawings, a roller member 61 is provided which is rotatably mounted by any suitable means such as bearings 62 upon the eccentric shaft 63. The shaft 63 extends through the upper and lower surfaces 14 and 12 of the housing 11 and is retained in position by any suitable means such as the enlarged annular collar 64 at the upper end and the nut 65 which is threadedly connected to the lower end of the shaft 63. The roller member 61 provides roller surfaces 66 and 67 which are adapted to abut the edges 68 and 69 of the lower and upper plates 47 and 46, respectively.

As previously noted, the rollers 31 are circumferentially spaced in each of the arcuate housing segments 15, 16, and 17 so that when the housing 11 is closed about the tubular member 19, the rollers 31 are circumferentially spaced about the rotary ring 32 so that when the rotary ring 32 is rotated, the surfaces 66 and 67 roll around and engage the outer peripheral edges 68 and 69 of the lower and upper plates 47 and 46, respectively. The central plate 45 extends into the recess 70 on member 61 formed between the roller surfaces 66 and 67 as shown in FIG. 6 of the drawings. The eccentric shaft 63 enables the roller member 61 to be adjusted relative to the edges 63 and 69 to compensate for wear.

As previously noted, the plates 14 and 12 extend laterally and define an opening 18 in the housing 11 as illustrated in FIG. 7 of the drawings. The central plate 45 of the rotary ring 32 extends inwardly relative to the opening 18 in the housing 11 and the edge 93 of each central plate 45 of each ring segment 41, 42, and 43, defines a circular opening 93a. The plate 45 supports the jaw segments 37, 3S, and 39 on the rotary ring 32 in a manner as will be described in greater detail hereinafter.

The jaw segments 37, 33, and 39 are generally arcuate in configuration, and each is provided with an arcuate slot 36a in its outer edge between the upper and lower surfaces of the jaw segments, in which slot the plate 45 of each ring segment is received as illustrated in FIG. 6 of the drawings. The slot 36a includes the sidewalls 36b and 350 spaced to slide on the surfaces 45b and 450 of each central plate 45, respectively. The edge 93 of each of the plates 45 abuts the end 36d of the slot in the jaw segment mounted thereon.

This construction enables the jaws to slide circumferentially on each central plate 45 but inhibits the jaws from becoming skewed in relation to each other or in relation to the plate 45 on which they are carried, thereby assuring that they are always in position to properly engage the pipe 19 when contacted therewith.

The jaw segments 38 and 39 are retained on the plate 45 of each of the rotary ring segments 42 and 43 by suitable means such as the arcuate window which is provided in each of the central plates 45 of each of the ring segments 42 and 43. This window is indicated in dotted line in FIG. 1 of the drawings. A pin 81 extends through the slot 35a in each of the jaw segments 38 and 39 and through each of the windows 80 in each of the central plates 45 to position the jaw segments 38 and 39 on their respective central plate 45. The window 80 is slightly larger in width than the diameter of the pin 81 to enable free movement of pin 81 in window 89.

The pin 81 may be threaded into the lower portion of the jaw segment as illustrated in FIG. 6 of the drawings if desired.

A suitable retaining means 84 may be removably secured by any suitable means to the housing segments 15, 15, and 17 to retain the rotary ring segments in position therein.

As previously noted, this arrangement accommodates circumferential sliding of each of the jaw segments 38 and 39 on each of the rotary ring segments 42 and 43 to enable the jaw segments 37, 38, and 39 to engage the pipe 19 properly and to enable the jaw segments to disengage from the tubular member 19 when desired. Suitable gripping members as illustrated at 82 are provided for engaging the surface of the pipe when the jaw segments are moved into contact with the pipe or tubular member 19.

The cam arrangement 40 which is provided for moving the jaw segments 37, 38, and 39 into engagement with the tubular member 19 includes the arcuate window 90 in the jaw segment 37, holes 91 and 92 positioned at each end of the window and in the central plate 45 of the ring segment 41, a pin 105 for fitting in either hole, and a recess or cam surface designated generally by the numeral 94 on the edge 93 of the plate 45 of ring segment 41. The slot 36a in the jaw segment 37 is illustrated as being cut away as shown in dotted line at 96 for receiving the roller also shown in dotted line at 97. The roller 97 is mounted on a pin 93 that extends through the jaw segment 37, and the roller 97 is positioned in the jaw segment 37 so that the outer peripheral edge 99 of the roller extends beyond the normal peripheral edge 36d of the slot in the jaw segment 37.

When the jaw segment 37 is in the position on the rotary ring segment 41 as represented in FIG. 1 of the drawings, the cam surface or cam surface or cam arrangement 4t) is inoperative to move the jaw segment 37 inwardly relative to the ring segment 41 to engage the tubular member 19. It will be noted that when the jaw segment 37 is in the position as illustrated in FIG. 1, the roller 97 is adjacent but slightly spaced from the central recess portion 95 in the cam surface 94 on the edge 93 of the central plate 45.

The edge 93 of the plate 45 on the segment 41 along with the edges 93 of each of the central plates 45 of each of the segments 42 and 43 define the circular opening 93a, as previously described, and as noted with regard to FIG. 6, the jaw segments in their normal position are adapted to abut the edge 93 of the central plate 45 and slide therealong. In order to operatively engage the tubular member 19 to impart rotation thereto, the jaw segments must be moved inwardly to engage the tubular member 19 whereupon the diameter of the opening 93 existing in the tong 10 between the jaw segments will be reduced sufliciently so that the jaw segments effect gripping of the tubular member 19. The pin 195 is adapted to be positioned in either of the openings 91 or 92 depending upon the direction of rotation of the rotary ring 32 and the direction of rotation in which it is desired to engage the tubular member 19 with the jaw segments 37, 38, and 39.

If the pin 195 is positioned as shown in FIG. 1, it is in the opening 91 and if the gear train in the tong 10 imparts rotation to the rotary ring 32 in a counterclockwise direction as represented by arrow 107, the segments 41, 42, and 43 will rotate together and upon initial rotation of the rotary ring 32, each of the jaw segments 37, 38, and 39 will tend to remain stationary relative to the central plate 45 on which they are each supported until the pin 81 in each of the jaw segments 38 and 39 engages the end of the groove or window whereupon they will then rotate in unison with the rotary ring 32.

The present invention provides an arrangement whereby one or more of the jaw segments 37, 38, and 39 may be more positively urged to gripping position with the tubular member 19, which arrangement also enables a more positive release of the jaw segments 37, 38, and 39 from the tubular member when desired. The means for accomplishing this is illustrated in two forms in FIGS. 1-4 of the drawings; however, it can be appreciated that other forms of the means as disclosed herein could be used Without departing from the scope of the invention. In FIG. 2, the means is referred to generally by the numeral 25%) and is shown as being mounted in the master jaw segment 37. As noted above, similar magnetic drag means could be employed on the other jaw segments, if desired. A portion of the housing 11 is shown in FIG. 2, namely, the upper portion 14 and the lower portion 12.

The means 259 is shown as being in the form of a permanent magnet formed of Alnico, and as shown in FIG. 2, the permanent magnet material is in the form of an arcuate channel 251 which extends circumferentially about the bottom portion of the master jaw segment. The slot 36a in each of the jaw segments forms upper and lower portions 36b and 360' on which the walls 36b and 36c are formed which slide on the surface 45b and 450 of the central plate 45, as previously noted.

Pins 252 are secured in the lower portion 360' by any suitable means such as threads or the like and depend downwardly therefrom, as shown in FIG. 2 of the drawings. Suitable openings 253 are provided in the arcuate channel magnet 251 which openings are slightly larger than the diameter of the pins 252 so that the magnet 251 may move vertically up and down on the pins 252. Any suitable number of pins may be used, and as illustrated in FIG. 1 of the drawings, three of such pins are employed. This tends to align the magnet 251 at all times and prevents skewing or misalignment of the magnet as it moves down on the pins 252. 4

The magnet 251 is provided with a coating of suitable material such as rubber or the like as shown at 253' in FIG. 2 on its upper surface to inhibit magnetic attraction between the magnet 251 and the lower portion 36' of the jaw segment 37. This causes the magnet 251 to be attracted towards the bottom wall 12 of the housing 11 and thereby drag or tend to inhibit movement of the main jaw segment 37 as the rotary ring 32 rotates. The bottom wall 12 of the housing is continuous and the magnetic means may drag therearound a full 3609. Thus, when rotation is imparted to the gear ring 32 as hereinabove described, the jaw segment 37 tends to remain stationary in the housing, and thus, the main segment 41 of the rotary ring 32 will move relative to the jaw 37 whereupon the roller 97 rides upon the cam surface 94 thereby forcing the jaw segment 37 radially against the tubular member 19. When this occurs, the opening between the jaw segments 37, 38, and 39 is decreased so that all of the segments engage the tubular member and grip it whereby continued rotation of the rotary ring 32 is transmitted to the tubular member 19.

This is more clearly illustrated in FIG. 10 of the drawings wherein it is seen that the rotary ring 32 has shifted circumferentially relative to the jaw segments 37, 38, and 39. As long as the rotary ring 32 is rotated in the direction of the arrow 107 when the pin 105 is in the hole 91, the jaw segments will be retained in engagement with the tubular member 19 as shown in FIG. 10. If the direction of rotation of the rotary ring 32 is reversed with the pin 105 in hole 91, the jaw segment 37 will again drag by reason of the magnetic attraction of the magnet 251 with the bottom wall 12 of the housing 11. Thus, the main ring segment 41 of the rotary ring 32 will move relative to the jaw 37 so as to disengage the peripheral edge of the roller 97 from the surface 94 to reposition the roller as illustrated in FIG. 1 of the drawings.

To aid in moving the jaw segment 37 from disengagement with the tubular member 19, the window 90 in the jaw segment 37 is constructed in a particular manner. As shown in FIG. 1 and more clearly illustrated in FIG. 10, the window 90 is also provided with a cam or sloping surface designated generally by 90f which includes the two sloping portions 90g and 90h, respectively, and the central recess portion 901'. When the main jaw segment 37 is engaged with the tubular member 19 and the direction of rotation is counterclockwise as illustrated and described with regard to FIG. 1, the pin 105 assumes the position in window 90 as shown in FIG. 10. Thus, when the direction of rotation of the ring 32 is changed to clockwise with the pin 105 in the hole 91, the pin 105 will strike the sloping surface 90g since the jaw segment 37 is restrained by the magnet 251, thereby delivering a jar to the segment which moves the jaw segment 37 radially outwardly from engagement with the tubular member 19. This releases the tongs 10 from tubular member 19.

Thus, thmagnet 251, the cam surface 40, and the arrangement of the window 90 with pin 105 therein cooperate to positivelyengage the jaw segment more quickly with the tubular member 19 upon rotation of the rotary ring 32 in a predetermined manner and also cooperate to more readily release the jaw segment 37 from engagement with the tubular member 19 when desired.

FIGS. 3 and 4 illustrate an alternate form of the drag means or restraining means, and it will be noted that in this form, a plurality of circumferentially spaced openings 260 are provided in the lower portion 36c of the jaw segment 37 in which are received plug magnets 262. If desired, an annular support or guide ring may be secured to the lower portion 360' around each of the openings 260, such guide being referred to by the numeral 263 to inhibit skewing or misalignment of the plug magnet 262 as it moves to engagement with the bottom wall 12 of the housing 11.

As can be seen in FIG. 3, a plurality of plug magnets is illustrated, and as previously noted, is spaced circumferentially about the jaw segment 37 so that the jaw segment 37 is restrained throughout its extent by the magnetic attraction between the plug magnets 262 and the bottom wall 12 of the housing 11. The plug magnets 262 are each provided with a suitable covering such as rubber as illustrated at 265 to maintain an air gap between the upper surface of the magnet and adjacent portions of the mechanism to reduce or inhibit magnet attraction of the upper side of the plug magnets with th jaw segment 37 or other parts of the mechanism. The housing or suitable portions thereof can be formed of suitable material which is responsive to magnetic flux of the magnets.

The pins 252 in the FIG. 2 modification and the openings 260 and the annular guide rings 263 in the FIG. 4 modification provide a means whereby the magnets 251 and 262, respectively, may move downwardly to engage the bottom wall 12 of the housing 11. Both forms of the invention function satisfactorily to restrain movement of the jaw segment 37 upon rotation of th rotary ring 32 so that a more positive and quicker engagement of the jaw segments 37, 38, and 39 with the tubular member 19 may be elfected and so that a more positive disengagement of the jaw segments with the tubular member 19 may be effected as desired.

While the magnetic means has been illustrated as being a permanent magnet, an electromagnet may be employed. In such event, the source of electrical energy, such as batteries or the like could be mounted on the housing or rotary ring. The electromagnet would be mounted on the jaw segment in a manner similar to that shown for the permanent magnet and suitable switching could be provided so that the electromagnet could be actuated externally by an operator. This would be of some advantage since the eifect of the magnet could then be eliminated when it is not needed or desired.

The magnetic means forms a frictional drag means for enabling relative movement between the rotary ring and jaw segments to be accomplished more quickly and more positively.

In FIG. 8, the lock means is illustrated generally by the numeral 120. In describing the lock or latch means 129, it should be noted that in connection with FIG. 1 and FIG. 7 of the drawings, the ring segment 41 of the rotary ring 32 is received within the housing segment 15 when the tong is open to receive the tubular member or immediately after the tong has been closed about a tubular member as illustrated in FIG. 7. Also, the ring segment 42 of the rotary ring 32 is received within the housing segment 16 and the ring segment 43 of the rotary ring 32 is received within the housing segment 17.

It will be noted that the housing segments 16 and 17 are each provided with an upstanding portion defining a recess, which portion is referred to generally at 121 in FIGS. 5, 7, and 8. The recess is formed in the upper surface 14 of the housing 11, and when the housing 11 and rotary ring 32 are closed about the tubular member 19, the housing segments assume the locked relation illustrated in FIG. 7 of the drawings. At this time, the lock means is positioned immediately below the recess 121 so that the lock means is as yet unactuated but ready to actuate to connect the segments 42 and 43 together.

The lock means 120 includes the block 123 which is adapted to fit in the recess 124 formed in the upper plate 46 at the end of the ring segment 42 as best seen in FIG. 9. It will be noted that the upper plate 46 of the ring segment 43 overlaps the center plate 45 of the segment 42 as bet illustrated in FIG. 8 of the drawings. Also, the lower plate 47 of the ring segment 43 underlaps the central plate 45 of the segment 42 so that when the segments 16 and 17 are abutted together, the central plate 45 of the ring segment 42 extends between the upper and lower plates 46 and 47 of the ring segment 43. This is the relative position of the adjacent ends of the ring segments 4-2 and 43 when the housing 11 and the segments 16 and 17 thereof are closed about a tubular member. In order to hold the block 123 in position in the recess 124 while accommodating up and down movement thereof, a groove or slot 125 may be provided on each side of the slot in plate 46 so as to receive the pin 126 therethrough as shown in FIGS. 8 and 9. This holds the block 123 in position in plate 46 of ring segment 42 and prevents it from falling out when the ring segments 42 and 43 are not engaged.

9 A roller 127 is mounted on the shaft 128 in block 123 and is adapted to abut the inner surface 129 of the upper plate 14 as rotation is imparted to the rotary ring 32.

A spring 130 tends to urge the block 123 and roller 127 outwardly relative to the upper plate 46 so as to abut the inner surface 129 of the plate 14 of the housing. The spring 130 is mounted in the recess 130a of the central plate 45 and surrounds the spindle 13%. The spindle 130b extends upwardly into the opening 130a and guides the block 123 as it moves up and down in the slot 124.

When the roller 127 is adjacent the raised portion 121 of the upper housing surface or plate 14, the block 123 by reason of the spring 130 acting thereon will urge it outwardly into the recess 121. The block 123 has the projection 131 depending therefrom which extends through plate 45 of ring segment 42, and when the rotary ring 32 is rotated so that the block 123 is moved out of the recess 121 and reseated in 124, then the block 123 will be depressed so that the projection 131 engages in the opening 132 in the lower plate 47 of the ring segment 43. This locks the segments 42 and.

43 together and prevents relative movement thereof. When the roller 127 is urged upwardly into the recess 121, the projection 131 is disengaged from opening 132.

The pivot pins 44, 45' and the latch or lock 120 form a rigid construction which prevents the ring segments 41, 42, and 43 of the rotary ring 32 from moving relative to each other.

In the operation and use of the present invention, the tong will be opened as shown in FIG. of the drawings in order to position it about a tubular member 19 whereupon the tong10 may be closed and will then assume the position shown in FIG. 7 of the drawings. Thereupon, the pin 105 may be positioned in either the hole 91 or 92, depending upon the desired direction of rotation of the rotary ring 32 to move the jaw segments 37, 38, and 39 into engagement'with the tubular member 19. i

In some instances, the pin 105 will be positioned in the hole 91 and the ring rotated in the direction as indicated by the arrow 107 whereupon the jaw segments 37, 38, and 39 are moved into engagement with the tubular member 19, and in other instances, it will be desired that the jaw segments 37, 38, and 39 engage the tubular member 19 and rotate it in the opposite direction. In this instance, the pin 105 will be positioned in the hole 92 and the rotation of the rotary ring will be in a clockwise direction, and in this event, the jaw segments 37, 38, and 39 will move into gripping relation with the tubular member 19.

The drag means as disclosed herein provides a magnetic drag which in effect has a single face magnetic attraction so that the magnet means will be attracted toward only one side of the housing 11. Also, the magnetic means may slide along the housing around the housing opening while magnetically engaged therewith in order to produce motion between the jaw segment and cam arrangement.

The magnetic means must be supported by at least one of the jaw segments in a manner, such as that disclosed herein, so as to exert the circumferential force on the jaw segment to produce the relative motion between the jaw segment and its support ring segment and to maintain this force on the jaw segment after relative movement between the jaw and ring segments has been completed and while rotation of all of the jaw and ring segments with the pipe gripped thereby continues. Additionally, the construction of the housing 11 and the manner of supporting the magnetic drag means must be such that the magnetic drag can be effective a full 360 in both a clockwise and counterclockwise direction.

As previously noted, the magnetic drag means of the present invention may be employed on other types of tongs, other than that illustrated in great detail herein.

Also, the cam arrangement including window 90, surface 90 and pin 105 may be used as a jar in other forms of tongs.

Most tong constructions include a support such as rotary ring or cage of some type which may be rotated either manually or by power. Suitable means, such as jaw segments, or the like, are adapted to be supported on the rotary ring or cage assembly and are movable radially to engage and grip a pipe or tubular member. The magnetic drag means of the present invention may be used on any tong of this general type. The magnetic flux of the magnetic drag creates a force that causes frictional resistance in the tong without affecting the other components in the tong and which overcomes the problems and difficulties encountered with mechanical drag means.

Additionally, the magnetic drag means is constructed and arranged so that it is effective the full 360 of rotation.

Broadly, the drag means in the form of the magnetic means described herein create relative movement between one or more jaw segments as rotation is imparted to a rotary ring or cage assembly in a tong, thereby causing the pipe engaging means, such as the jaw segment, to move quickly and more positively into engagement with a tubular member or pipe, and the drag means also function to more quickly release the jaw segments from engagement with the tubular member 19.

Additionally, when the rotary ring 32 is rotated to release the jaw segments 37, 38, and 39, the cam surface designated generally by the numeral 90 formed on the edge of the window 90 cooperates with the pin 105 to jar and release the jaw segments from engagement with the tubular member, as previously described herein.

What is claimed is:

1. A power tong for rotating tubular members including a rotary ring having gear teeth on its outer periphery whereby it may be rotated to transmit rotation to a tubular member about which said rotary ring is positioned, said rotary ring being formed of segments with two segments being pivotally mounted on a third segment whereby said rotary ring may be opened to receive a tubular member therein and thereafter closed about the tubular member, jaw segments slidably mounted on each of said rotary ring segments and extending substantially circumferentially about the tubular member to grip it, a plurality of roller means circumferentially spaced to support said rotary ring, a housing to support said roller means, said housing being formed in segments which are pivotally connected together whereby it may be opened simultaneously when said rotary ring is opened to receive the tubular member therein, lock means on said two rotary ring segments cooperating when said rotary and housing are closed to lock said rotary segments together against relative movement when rotation is imparted to said rotary ring, magnet means slidably engaging said housing and one of said jaw segments together to restrain rotation of said segment when rotation is imparted to said rotary ring, and cooperating cam surface means on one of said rotary ring segments and said one jaw segment whereby rotation of said rotary ring relative to said restrained jaw segment engages said cooperating cam surface means to feed said jaw segments to gripping relation with the tubular member, said c0- operating cam surface means including a roller mounted on said jaw segment, a recessed portion on said rotary segment adjacent said roller whereby rotation of said rotary segment engages said roller and recessed portion and forces said jaw segment inwardly to grip the pipe, means to actuate said cam surface means in either direction of rotation of said rotary ring and to release said jaws from the tubular member in either direction of rotation, said last named means including a window in said jaw segment, openings at each end of said window in said rotary ring, and pin means for fitting in either of said prevent engagement of said jaws with the tubular member .but accommodating a relative movement between said jaw and segment in the other direction to force said jaw segment into engagement with the tubular member, said window having a sloping surface thereon against which said pin engages when said rotary ring and segments are rotated in a direction to disengage from the tubular member, said engagement of said pin and sloping surface producing a radial movement of said one jaw segment away from the tubular member.

2. The invention recited in claim 1 wherein said magnet means is a curved channel magnet, and means supporting said magnet for producing a drag between said housing and jaw segment during the full 360 rotation of said rotary ring.

3. The invention recited in claim 1 wherein said magnet means is a plurality of plug magnets circumferentially spaced relative to said one jaw segment, and means supporting said magnet for producing a drag between said housing and jaw segment during the full 360 rotation of said rotary ring.

4. In a reversible rotary powerrtong for engaging a tubular member, the invention comprising,

(a) a segmented housing,

(b) a segmented rotary ring supported for rotation relative to said housing,

(a) jaw segments on each segment of said rotary ring,

(d) at least one of said jaw segments and rotary ring segments having a cooperating cam surface arrangement which moves the jaw segment radially of said housing to contact *the tubular member upon rotation of said ring in said housing,

(e) magnetic means positioned between at least one of said jaw segments and said housing to slide said segment along and relative to said housing for producing a continuous dragging force for 360 of rotation of said ring relative to said housing'which thereby aids in actuation of said cooperating cam surface arrangement,

(f) said cooperating cam surface arrangement including a roller mounted on said jaw segment, and a recessed portion on said rotary segment adjacent said roller whereby rotation of said rotary segment engages said roller and recessed portion and forces said jaw segment inwardly to grip the pipe,

(g) and additional means to actuate said cam surface arrangement in either direction of rotation of said rotary ring and to release said jaws from the tubular member in either direction of rotation.

5. The combination recited in claim 4 wherein said additional actuating means includes a window in said jaw segment, openings at each end of said window in said rotary ring, and pin means for fitting in either of said openings whereby said pin locks said jaw segment and ring segment for rotation together in one direction to prevent engagement of said jaws with the tubular member, but accommodating a relative movement between said jaw and segment in the other direction to force said jaw segment into engagement with the tubular member, said window having a sloping surface thereon against which said pin engages when said rotary ring and segments are rotated in a direction to disengage from the tubular member, said engagement of said pin and sloping surface producing a radial movement of said one jaw segment away from the tubular member.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A POWER TONG FOR ROTATING TUBULAR MEMBERS INCLUDING A ROTARY RING HAVING GEAR TEETH ON ITS OUTER PERIPHERY WHEREBY IT MAY BE ROTATED TO TRANSMIT ROTATION TO A TUBULAR MEMBER ABOUT WHICH SAID ROTARY RING IS POSITIONED, SAID ROTARY RING BEING FORMED OF SEGMENTS WITH TWO SEGMENTS BEING PIVOTALLY MOUNTED ON A THIRD SEGMENT WHEREBY SAID ROTARY RING MAY BE OPENED TO RECEIVE A TUBULAR MEMBER THEREIN AND THEREAFTER CLOSED ABOUT THE TUBULAR MEMBER, JAW SEGMENTS AND EXTENDING SUBSTANTIALLY CIRCUMFERENTIALLY ABOUT THE TUBULAR MEMBER TO GRIP IT, A PLURALITY OF ROLLER MEANS CIRCUMFERENTIALLY SPACED TO SUPPORT SAID ROTARY RING, A HOUSING TO SUPPORT SAID ROLLER MEANS, SAID HOUSING BEING FORMED IN SEGMENTS WHICH ARE PIVOTALLY CONNECTED TOGETHER WHEREBY IT MAY BE OPENED SIMULTANEOUSLY WHEN SAID ROTARY RING IS OPENED TO RECEIVE THE TUBULAR MEMBER THEREIN, LOCK MEANS ON SAID TWO ROTARY RING SEGMENTS COOPERATING WHEN SAID ROTARY AND HOUSING ARE CLOSED TO LOCK SAID ROTARY SEGMENTS TOGETHER AGAINST RELATIVE MOVEMENT WHEN ROTATION IS IMPARTED TO SAID ROTARY RING, MAGNET MEANS SLIDABLY ENGAGING SAID HOUSING AND ONE OF SAID JAW SEGMENTS TOGETHER TO RESTRAIN ROTATION OF SAID SEGMENT WHEN ROTATION IS IMPARTED TO SAID ROTARY RING, AND COOPERATING CAM SURFACE MEANS ON ONE OF SAID ROTARY RING SEGMENTS AND SAID ONE JAW SEGMENT WHEREBY ROTATION OF SAID ROTARY RING RELATIVE TO SAID RESTRAINED JAW SEGMENT ENGAGES SAID COOPERATING CAM SURFACE MEANS TO FEED SAID JAW SEGMENTS TO GRIPPING RELATION WITH THE TUBULAR MEMBER, SAID COOPERATING CAM SURFACE MEANS INCLUDING A ROLLER MOUNTED ON SAID JAW SEGMENT, A RECESSED PORTION ON SAID ROTARY SEGMENT ADJACENT SAID ROLLER WHEREBY ROTATION OF SAID ROTARY SEGMENT ENGAGES SAID ROLLER AND RECESSED PORTION AND FORCES SAID JAW SEGMENT INWARDLY TO GRIP THE PIPE, MEANS TO ACTUATE SAID CAM SURFACE MEANS IN EITHER DIRECTION OF ROTATION OF SAID ROTARY RING AND TO RELEASE SAID JAWS FROM THE TUBULAR MEMBER IN EITHER DIRECTION OF ROTATION, SAID LAST NAMED MEANS INCLUDING A WINDOW IN SAID JAW SEGMENT, OPENINGS AT EACH END OF SAID WINDOW IN SAID ROTARY RING, AND PIN MEANS FOR FITTING IN EITHER OF SAID OPENINGS WHEREBY SAID PIN LOCKS SAID JAW SEGMENT AND RING SEGMENT FOR ROTATION TOGETHER IN ONE DIRECTION TO PREVENT ENGAGEMENT OF SAID JAWS WITH THE TUBULAR MEMBER BUT ACCOMMODATING A RELATIVE MOVEMENT BETWEEN SAID JAW AND SEGMENT IN THE OTHER DIRECTION TO FORCE SAID JAW SEGMENT INTO ENGAGEMENT WITH THE TUBULAR MEMBER, SAID WINDOW HAVING A SLOPING SURFACE THEREON AGAINST WHICH SAID PIN ENGAGES WHEN SAID ROTARY RING AND SEGMENTS ARE ROTATED IN A DIRECTION TO DISENGAGE FROM THE TUBULAR MEMBER, SAID ENGAGEMENT OF SAID PIN AND SLOPING SURFACE PRODUCING A RADIAL MOVEMENT OF SAID ONE JAW SEGMENT AWAY FROM THE TUBULAR MEMBER. 